Sanding drum



F. HARRIS SANDING DRUM May 7, 1946.

Original Filed Feb. 11, 1942 INVENTOR F'onjs Z 1-63 rris ATTORNEYS Patented May 7, 1946 "UNITED; STATE v SANDING DRUM .Forist Harris, Merced, Calif.

" original application Fbbruary,11,'1942,seria1 No; 430,374, now PatentNo. 2,375,102, dated May 1,

1945,Serial N0.'5 78 ,'388

Claims. (01. 51- 194) This invention relates" in general to floor sanding machines, and in particular the invention is directed to, and itis an object to provide, a sanding drum including unique means for readily and quickly attaching an ini tially separate sanding strip to the drum in helically wound relation whereby said strip is continuous circumferentially of the drum and from end to end thereof,

The present application is a division as to all common subject matter of. copending application, Serial No. 430,374, filed February 11, 1942, on Floor sand machine, now Patent No. 2,375,102, issued May 1, 1945.

Another object of the present invention is to embody, in a floor sanding machine drum, means for maintaining the helically wound sanding strip under tension and taut about the drum at all times; such means including a spring arranged to constantly exert a pull on the strip from one end thereof, the other end of the strip being attached to said drum.

A further object of the invention is to produce a simple and inexpensive device, and yet one which Will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a plan view of a sanding drum, detached, embodying the present invention.

Figure 2 is an enlarged fragmentary plan view, partly in section, and with the sanding strip partly broken away, to show the strip tensioning device as in use.

Figure 3 is an enlarged fragmentary plan view of the end of the sandin drum which carries the tensioning device; the adjacent end of the sanding strip being turned back, and the tensioning device being shown in its retracted potion preparatory for engagement with said adjacent end of the sanding strip.

Figure 4 is a fragmentary cross section on line 4-4 of Fig. 2 showing the tensioning device as connected with the adjacent end of the sanding strip.

Referring now more particularly to the characters of reference on the drawing, the numeral l indicates the drum of a sanding machine, which includes end shafts 2 adapted to be jourividedand this application February 17,

naled in the sanding machine, and which end shafts carry drive pulleys 3. The drum l is circumferentially faced from end to' end thereof with a semi-resilientmaterial, such as a thick felt pad 4.

ends of the drum l;.said pointed'ends of 'the strip being indicated at 6 and'l, respectively.

At one end of the drum the pointed end 6 is secured to said drum by a removable pin or the like, as indicated at 8. At the other end of the drum the pointed end 1 of the strip 5 is Secured by a headed pin 9 to a plunger I0 slidable in a cylinder ll embedded in the pad 4 just under the sanding strip and disposed parallel to the slope or pitch of the spiral or helix; the pin riding in a longitudinal slot S formed in the top of said cylinder. The cylinder II is attached to the drum l by cars I2 having screws l3 passing therethrough into said drum.

The head of pin 9 is disposed slightly inwardly of the outer face of the pad 4, and the adjacent pointed end 1 of strip 5 has an aperture l4 therethrough adapted to engage about pin 9 be neath the head of the latter.

The plunger is normally urged outwardly or toward the adjacent end of the drum by a spring I5 in the cylinder behind the plunger, so as to always maintain a tension on the strip 5 and to take up any slack in the latter as the same becomes more tightly wrapped about the drum with driving rotation of the same.

In order to enable the plunger to be positively retracted in the cylinder preparatory to engagement of the pin 9 through the aperture M in the adjacent pointed end 1 of the strip 5, the outer end of the cylinder II is tapped, as at l6, for engagement with a screw or bolt ll, whereby the advance of this screw will retract the plunger to the desired extent. When connection of the pin 9 with the pointed end I has been made, the screw I1 is withdrawn and thereafter the plunger, and the strip secured thereto, are subject to the tension of spring l5.

From the foregoing description it will be readily seen that I have produced such a. device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may -be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described my invention, what is claimed as new and useful and upon which Letters Patent is desired is 1. In a sanding machine drum, a sanding strip Wrapped helically about the drum from end to end thereof, means to secure the strip at one end on the drum in a fixed position, a spring-V advanced plunger, means mounting the plunger on the drum guided longitudinal movementsubestantially parallel to the pitch of the helix of the strip and attached adjacent the of" the latter, and means to securethe plunger-to said other end of the strip;' said plungerfunctioning to exert a continuous pull on said strip in a direction to closely wrap the same about the drum.

2. In a sanding machine, a sanding drum, a sanding strip wrapped helically aboutfthe. drum from end to end, means to secure the strip at one end on the drum at one end thereof, a cylinder mounted on the drum at the other end under the strip adjacent the corresponding end thereof and substantially parallel to the slope of the helix, a plunger slidable in the cylinder, a spring behind the plunger tending to force the same out, and a securing pin projecting through the strip and into the plunger.

3. In a sanding machine, a sanding drum, a

sanding strip wrapped helically about the drum from end to end, means to secure the strip at one end on the drum at one end thereof, a cylinder mounted on the drum at the other end under the strip adjacent the corresponding end thereof and substantially parallel to the slope of the helix, a plunger slidable in the cylinder, a

spring behind the plunger tending to force the same out, and means securing; the; adjacent end of the strip to said plunger.

4. In a sanding machine, a sanding drum, a sanding strip wrapped helically about the drum from end to end, means to secure the strip under the strip adjacent the corresponding end thereof and substantially parallel to the slope of the helix, a plunger slidable in the cylinder, a

' behind the, plunger tending to force the same out, and means securing the adjacent end ofthe strip to said plunger; the drum including a semi-resilient facing of substantial thickness and the cylinder being fully embedded in said facing, said securing means comprising a headed pin projecting outwardly from; the plunger with the head of said pin disposed inwardly of the periphery of said facing.

5, A sanding drum, as in claim 2 in which the outer end of the cylinder is exposed to the corresponding end of the drum; the outer end portion of said cylinder being tapped for the reception of a screw adaptedto engage and retract the plunger against the action of the spring.

FORIST HARRIS. 

